diff --git a/common/dlcservice_interface.h b/common/dlcservice_interface.h
index aa24105..3524d50 100644
--- a/common/dlcservice_interface.h
+++ b/common/dlcservice_interface.h
@@ -34,6 +34,14 @@
   // On failure it returns false.
   virtual bool GetInstalled(std::vector<std::string>* dlc_module_ids) = 0;
 
+  // Returns true if dlcservice successfully handled the install completion
+  // method call, otherwise false.
+  virtual bool InstallCompleted(const std::vector<std::string>& ids) = 0;
+
+  // Returns true if dlcservice successfully handled the update completion
+  // method call, otherwise false.
+  virtual bool UpdateCompleted(const std::vector<std::string>& ids) = 0;
+
  protected:
   DlcServiceInterface() = default;
 
diff --git a/common/dlcservice_stub.cc b/common/dlcservice_stub.cc
index c5f9306..3dcb2e0 100644
--- a/common/dlcservice_stub.cc
+++ b/common/dlcservice_stub.cc
@@ -33,4 +33,11 @@
   return true;
 }
 
+bool DlcServiceStub::InstallCompleted(const vector<string>& ids) {
+  return true;
+}
+bool DlcServiceStub::UpdateCompleted(const vector<string>& ids) {
+  return true;
+}
+
 }  // namespace chromeos_update_engine
diff --git a/common/dlcservice_stub.h b/common/dlcservice_stub.h
index 4e12c11..9b27971 100644
--- a/common/dlcservice_stub.h
+++ b/common/dlcservice_stub.h
@@ -32,6 +32,8 @@
 
   // BootControlInterface overrides.
   bool GetInstalled(std::vector<std::string>* dlc_module_ids) override;
+  bool InstallCompleted(const std::vector<std::string>& ids) override;
+  bool UpdateCompleted(const std::vector<std::string>& ids) override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DlcServiceStub);